OK, this is going to sound weird, but I only have a "ladder" on the back - where I'm going from needle 3 to needle 1.
As this is my very first attempt at socks, I am only doing one at a time (actually had never heard of the "one inside the other" thing)....and I was still confused by the video.
I don't quite understand why my other "switches" are smooth and the join above the heel is "ladder-y"....any clues?